Plug screw feeders of the type which utilize a rotatable feed screw are utilized in pulp manufacturing processes. Such processes involve feeding lignocellulosic material, such as wood chips, wood shavings and sawdust, or various non-wood fibers, such as sugarcane bagasse, from a hopper or storage container equipped with the screw feeder to further processing equipment. This further processing equipment can include mechanical refiners or disk refiners, as well as digesters and other pulp treatment devices, such as impregnating equipment. During the infeeding process, the conical screw of the screw feeder compresses the chips into a dense plug which serves to seal against the impregnator vapor pressure, for instance. The chip plug is advanced continuously as it expands into the impregnator, while water present in the chips is drained off through holes in the screw housing. The chip plug is moved in the impregnator towards a conical back-blowing mechanism, which breaks up the plug.
A principal object of the present invention is a means for dealing with the problem of providing a screw feeder that is able to take up the rotational loads and alternating axial loads that occur therein. These loads place the equipment under a great deal of strain, and serious wear will thus occur unless the screw feeder is accurately centered and stable.